Syntetic oil, lead additive and other questions - Impala Tech
General Tech For best results use forums below.

 
LinkBack Thread Tools
post #1 of 21 (permalink) Old 08-13-2009, 01:11 PM Thread Starter
Lifetime Premium Member
 
Join Date: Jan 2009
Location: Northern Hemisphere
Posts: 901
 
Syntetic oil, lead additive and other questions

Here is a couple of questions that I hope can be answered to clear few things for me:

1. Would I benefit from going to synthetic oil now on my 74K miles SBC 350 (as far as I can tell it is the original engine). I have no idea if the engine was rebuilt or not but most likely not with such a low mileage. I did hear that switching from regular to synthetic oil cleans things up (build-up) but can also introduce leaks.

2. What about the hardened valve seats? Again, I have no idea if they were hardened or not. So far I have made about 2000 miles and I see no signs of anything going wrong with the engine. From all the articles I read, they should recess after about 1000 miles of everyday driving.

3. Lead additive. Should I add it or not? I am pumping mid-grade (89) gas now and have no problems with pinging or anything. It is my daily driver so spending $10 on additive for every gas tank gets expensive when I have to visit gas station every few days.

Thanks.
drabina is offline  
Sponsored Links
Advertisement
 
post #2 of 21 (permalink) Old 08-13-2009, 02:14 PM
Moderator
 
Join Date: Jul 2009
Location: Canada
Posts: 1,402
 
You can switch to synthetic. It doesn't make leaks. If you have a leak, it will still leak.

What year is your engine? GM went to low-compression, lead-free compatible engines for 71, so all you need is regular 87 without any additives if it is 1971 or later.
jayoldschool is offline  
post #3 of 21 (permalink) Old 08-13-2009, 02:16 PM Thread Starter
Lifetime Premium Member
 
Join Date: Jan 2009
Location: Northern Hemisphere
Posts: 901
 
The engine is 1970 SBC 350. Based on the casting numbers, it is correct engine for the year.
drabina is offline  
 
post #4 of 21 (permalink) Old 08-13-2009, 03:33 PM
Moderator
 
Join Date: Jan 2006
Posts: 12,459
 
You have 10.25:1 compression in a stock SBC from 1970 instead of the 8.7:1 that was used from 1973 and up. If you are not pinging then I wouldn't worry about it. Stock exhaust valves in the small block where 1.50" hardened steel with a spun welded head. You won't have to worry about the valve being defaces as much as the seat as the valve is harder. With aftermarket tuliped stainless steel valves the seat is doing the beating and the valve looses it's seal with time. Either way it is a gradual process and not as bad as the engineers first thought.

Synthetic oil is just oil that has been much more highly refined than regular organic dead dyno juice. Oil is a non-homogenous mixture of many polymers. With synthetic oils they pick one they like and break apart all of the hydrogen bonds of organic oil to reduce it to a protein soup, and then recombine the chains again to match what ever they stick in the pressure pot for a catalyst. What comes out is all the same flavor as far as the hydrocarbon chains go. I see no advantage and I only run the cheapest stuff on sale at Wally world and change it every 3,000 miles.

They do the exact same thing with gasoline to get that high 87 octane no one likes. But you would like the roughly 45-60 octane soup that comes out of the distillation tower even less. They take gasoline and break it down in a pressure cooker that holds thousands of gallons of gas and heat it till it falls apart then recombine it under pressure and more heat to form out grades of gas (which explains why when there is an explosion at a refinery it is usually noticeable). A lead additive is highly toxic and carcinogenic, I wouldn't use it. If you need higher octane move up a grade at the pump. If you need more than 93 octane you can add toluene (lacquer paint thinner) to the gasoline to raise the octane rating up to about 104.

Big Dave
Big Dave is online now  
post #5 of 21 (permalink) Old 08-13-2009, 03:59 PM
Senior Member
 
Join Date: Jun 2009
Location: GA.
Posts: 402
 
As for synthetic oils I have used it in the past but found that regular oil don't leak as bad. Synthetic oil don't cause leaks it is just thinner oil so it leaks a bit more than conventional oil. I also used a lead substitute on my 72 400 sbc could not tell the difference. I always used Chevron gas with techron ran best with that. I did have the motor rebuilt after wards. It is now set to run lower grade gas but I usually run a octane booster every now and then.

Make: Chevrolet
Model: Impala
Year: 1971
Doors: 4
Motor: 400 V8
Tranny: TH350
71 Impala is offline  
post #6 of 21 (permalink) Old 08-13-2009, 07:09 PM Thread Starter
Lifetime Premium Member
 
Join Date: Jan 2009
Location: Northern Hemisphere
Posts: 901
 
Thanks for all the replies. My questions are answered and based on that I will... do nothing :-) I will continue using regular oil, put mid-grade gas and not worry about the valve seats. If anything goes bad, my engine will probably be due for a rebuild anyway.
drabina is offline  
post #7 of 21 (permalink) Old 08-13-2009, 10:16 PM
Moderator
 
Join Date: Jan 2006
Posts: 12,459
 
Of all the retail oils available at a "normal" price range Shell Rotella T is about the best for your application. It has about two thirds the ZDDP that was found in motor oils from ten years ago, which is more than the half that is out there now under the API SM GF-4 rating. It is also full of detergent which should clean out the gunk and varnish build up. If you don't mind paying six to seven bucks a quart for motor oil Q-state Racing has the highest level of ZDDP of any motor oil tested currently.

Your older motor most likely has a flat tappet cam installed and will need some soothing zinc and phosphorous to keep it purring away. One good thing in your favor is that a stock Chevy tappet is one of the best made ones in the industry with a hardened steel tool bottom welded to a machined steel shell.

Big Dave
Big Dave is online now  
post #8 of 21 (permalink) Old 08-13-2009, 10:28 PM Thread Starter
Lifetime Premium Member
 
Join Date: Jan 2009
Location: Northern Hemisphere
Posts: 901
 
Which Rotella T should I use, the synthetic one (blue bottle) or regular one (white bottle)? They are about $20 and $14 respectively (that's per gallon) so not that expensive.

I do not change my oil but I guess I could bring my own to the place that services my car.
drabina is offline  
post #9 of 21 (permalink) Old 08-13-2009, 10:56 PM
Moderator
 
Join Date: Jan 2006
Posts: 12,459
 
I wouldn't advise that (it is like bringing food to restaurant and asking them to cook it for you). Most 15 minute shops have Rotella on the shelf to satisfy the diesel truck owners. It will just be more expensive at a quick change place than at Walmart. You can easily change your oil and filter with a plastic pan and a set of drive on ramps that Wally world also has in their automotive section. The old oil goes back in the empty jug and who ever sells it to you is required by law to recycle it (I wish they included anti-freeze in that law but they didn't).

Big Dave
Big Dave is online now  
post #10 of 21 (permalink) Old 08-13-2009, 11:04 PM Thread Starter
Lifetime Premium Member
 
Join Date: Jan 2009
Location: Northern Hemisphere
Posts: 901
 
I know the guys that change the oil for me. They wouldn't mind as long as they do not have same oil in stock. Actually, the first time I brought my wagon there they asked me if I brought oil with me.
drabina is offline  
post #11 of 21 (permalink) Old 08-14-2009, 10:41 AM
Senior Member
 
Join Date: Jun 2008
Location: Near Chicago
Posts: 703
 
Additives

On a normal performance engine I wouldn't worry about the valve seats. Engines with stiffer valve springs and higher RPM use should have hardened valve seat installed.

As for the ZDDP; from my experience, I am running a pretty healthy cam in my supercharged Camaro engine and that engine was built back in '94. I have used Castrol Racing Oil and others up until last year when I started reading about this ZDDP issue and started adding ZDDP. Had no problems and the engine has a fair amount of mileage on it running some different SAE ratings over the years. I think the ZDDP is most important in newer flat tappet engines, but an engine that has been running over the years as the Zync ratings have gradually lowered wouldn't seem in as much danger, if you've been running higher performance oils or semi-synth blends. I do change my oil a lot in my Camaro since supercharged engines can have more blow-by and fuel contamination, but again never added ZDDP until last year or so.

I use both ZDDP additive and lead booster in my Caprice 396 since it is a fresh rebuild with a healthier Summit flat tappet hydraulic cam and runs 10.25:1 compression.

-Scott
1968 Caprice 396 is offline  
post #12 of 21 (permalink) Old 08-14-2009, 06:40 PM
Moderator
 
Join Date: Jan 2006
Posts: 12,459
 
ZDDP isn't just for a flat tappet cam. It lengthens ring life and bearing life by protecting any high pressure area (even the oil pump itself) where you have metal in close proximity separated by a film of oil. A bronze distributor gear will not last as long with reduced ZDDP as it will with racing oil which is rich in ZDDP. Other alternatives is chrome plated rings, and plastic distributor gears if you run a roller cam and do not need the higher ZDDP.

Big Dave
Big Dave is online now  
post #13 of 21 (permalink) Old 08-16-2009, 06:11 PM
Member
 
Join Date: Oct 2006
Location: Oregon
Posts: 90
 
Not looking to beat a dead horse here, as it sounds like drabina has had all questions responded to with good advice, so I'm just throwing in my two cents:

I run a stock `68 L72 427 in my Z24 Impala with 11:1 compression. The car has ~43k original miles on it, and the last thing I would ever want to do is damage or destroy this engine as it is original to the car. I don't disagree with anyone else's advice here, so this is just an FYI to give you some additional perspective on what's worked best for me over the years. My car probably see's about 500-600 miles per year.

> I have been using Mobil-1 10W-30 Synthetic oil for about 5 years with no leak issues whatsoever. I ran Penzoil organic 10W-30 prior to that. The Synthetic oil is probably more for my own piece of mind more than anything else, as I can't honestly say that I've noticed any significant performance difference. I just believe it provides superior wear protection, and is worth the extra cost.

> This is a solid lifter engine w/o hardened valve seats. I do add ZDDPlus with every oil change (about every 1000 miles, or once a year). I buy this through Dennis Kirban:

http://www.kirbanperformance.com/pro...+ADDITIVE.html

> While it may not be practical (or necessary) for you to use a lead additive for a daily driven `70 350 small block, but with 10.25:1 compression I would think you would at least want to use a 92 octane premium pump gas for the best performance. I use Chevron 92 as a starting point with every fill-up, then add 4 qts. of Octanne Supreme 130 with real TEL, 12 ounces of Chevron Octane Booster, and a couple of pints of Stabil (just because the car sometimes sits for extended periods between being driven). This puts the octane level in my 24 gallon tank up to about 112. Any lower than this with the L72, and I will experience detonation issues. Octane 130 Supreme can only be purchased on-line, and I buy it here through Battery-Stuff.com:

http://www.batterystuff.com/fuel-treatments/

Yes, this all gets expensive, but again, is worth while in my opinion to keep a higher compression engine running as it should. Remember, back in the late 60's/early `70's, Lead and 112 octane fuel was pump gas, and ZDDP was in your oil. This is what these engines were desinged to run on.

BTW: I believe in being as "green" as anyone else and as I mention, I limit the use of my collector cars to summer time cruise-in's and shows.

Hope the information helps.

Bigblox
Bigblox is offline  
post #14 of 21 (permalink) Old 08-16-2009, 09:49 PM
Moderator
 
Join Date: Jan 2006
Posts: 12,459
 
Like I said the major refiners add toluene (lacquer paint thinner) to their 87 octane to raise the octane to 92. You can add more of it to raise it up to 104 (which will support 12.5:1 octane because that was the octane rating on Sunoco 260 blue that was sold at the corner gas station back in the good old days and was added to American White lead free gas to get the pump gas up to 102 octane as well back in the late sixties. There are other aromatics that you can use to raise the octane even higher, but they are not sold at the corner auto parts store the way lacquer thinner is.

Big Dave
Big Dave is online now  
post #15 of 21 (permalink) Old 08-17-2009, 08:08 AM Thread Starter
Lifetime Premium Member
 
Join Date: Jan 2009
Location: Northern Hemisphere
Posts: 901
 
Thanks again.

I can switch from mid-grade to premium gas (91) but like I said the car runs like a dream now. As to the other additives, I guess I am going to skip them. The engine is most likely original but it is also my daily driver. If it dies in few years then all the money saved by skipping the additives would go toward new engine.
drabina is offline  
post #16 of 21 (permalink) Old 08-17-2009, 01:27 PM
Senior Member
 
Join Date: Jan 2009
Location: Philadelphia, PA
Posts: 464
Blog Entries: 13
 
Send a message via AIM to medisalle
Hmm.. How much Toluene do you add per gallon to make a decent mix? I don't have any issues with performance on my sewing-machine inspired 230 6cyl (in my '63) - but my '67 Fury with the stock 383 needs higher octane to run well.. I've never heard of the toluene fix!

The things I learn here ! It's amazing!
medisalle is offline  
post #17 of 21 (permalink) Old 08-17-2009, 01:32 PM
Moderator
 
Join Date: Jul 2009
Location: Canada
Posts: 1,402
 
Ok, I am getting some conflicting info. I recently bought the synthetic (blue jug) Rotella to run in my 65 250hp 327. However, I have been told that the ZDDP has been dropped in diesel oils as well, due to the use of cats on the newest diesels and emission requirements. So... what's the right answer? I can go out to the garage and get the specs of the jug if we need it...

Jason.
jayoldschool is offline  
post #18 of 21 (permalink) Old 08-17-2009, 02:49 PM
Moderator
 
Join Date: Jan 2006
Posts: 12,459
 
Shell Rotella Tas bottled today is right at 1100 ppm ZDDP and racing oil is at 1800 ppm. Standard synthetic oils sold as motor oil conmtain 900 ppm. A flat tappet cam requires 1600 ppm to survive. You have two options. Add ZDDP as an oil additive, or switch to a roller cam like I did (and the automotive world did twenty five years ago).

Big Dave
Big Dave is online now  
post #19 of 21 (permalink) Old 08-17-2009, 03:18 PM Thread Starter
Lifetime Premium Member
 
Join Date: Jan 2009
Location: Northern Hemisphere
Posts: 901
 
So even with Rotella T we should be using ZDDP, correct? I guess it is more convenient to use racing oil instead.

The only thing is that Q-Racing oil is rated either at 0W5 or 17.5W35. That's not very suitable for daily driver that's used most of the year (excluding extreme winter conditions).
drabina is offline  
post #20 of 21 (permalink) Old 08-17-2009, 05:08 PM
Moderator
 
Join Date: Jul 2009
Location: Canada
Posts: 1,402
 
Thanks, Big Dave. So... how much GM EOS gets added to my Rotella T Synthetic to bring it up to what it needs to be?
jayoldschool is offline  
post #21 of 21 (permalink) Old 08-17-2009, 05:22 PM
Moderator
 
Join Date: Jan 2006
Posts: 12,459
 
Quote:
Originally Posted by jayoldschool View Post
Thanks, Big Dave. So... how much GM EOS gets added to my Rotella T Synthetic to bring it up to what it needs to be?
A quarter of a bottle should do it.

Big Dave
Big Dave is online now  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Impala Tech forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome